Integrated external cavity distributed Bragg reflector laser.
01 January 1987
The fabrication and performance characteristics of a new single frequency integrated external cavity distributed Bragg reflector lasers are described. The current is confined to the active region of these lasers using semi-insulating Fe-doped InP layers. The semi-insulating layer also provides lateral index guiding to the lasing optical mode both in the active and the passive cavity sections. The lasers emit near 1.52microns. The threshold current of these lasers are in the range 70-120mA. CW linewidth of 2.2 MHz has been obtained for a 5 mm long laser at an output power of 6 mW. Lasers with longer external cavity and higher mode coupling between the active and the passive cavity sections should exhibit lower CW linewidth. The laser structure described here can be fabricated using the vapor phase epitaxy growth technology which by virtue of the possibility of large wafer sizes can allow (>1 cm) external cavities and hence very narrow linewidth.